1. Field of the Invention
The present invention relates to a display device using electroluminescence and a manufacturing method of the same.
2. Description of the Prior Art(s)
An OLED (Organic Light Emitting Diode), that is, an organic EL (Electro Luminescent) element attracts attention as a thin and light-weight light-emitting source, and an image display device including many organic EL elements is developed. The organic EL element has a structure in which at least one layer made of an organic material is sandwiched between a pixel electrode and an opposite electrode.
An image display device using electroluminescence typically includes an element substrate on which organic EL elements are arranged in a matrix form correspondingly to pixels and an opposite substrate disposed to be opposite to the element substrate. A structure including color filters arranged in a matrix form correspondingly to the pixels is formed on the opposite substrate. A light emitted from the organic EL element is directed from the element substrate to the opposite substrate, passes through the color filter and outgoes. A black matrix to prevent lights from adjacent organic EL elements from being mixed is normally provided at boundaries of the color filters.
The color filter is made of a resin material having light selective transparency, or the like. The black matrix is formed by using, for example, a photolithography technique to pattern a light shielding film laminated under or on the color filter. That is, the black matrix is selectively formed at the pixel boundary by a patterning process of, for example, etching the light shielding film to remove it from an area other than the pixel boundary. The light shielding film is made of, for example, a metal material such as chromium (Cr).